Doffer assembly



H. F. PARKER-[ON DOFFER AS S EMBLY Filed Jan. 4, 1965 HOWARD E PARKERTUN 3K /Nl/E/vrox? MVM ,4 TTCORNEKS' United States Patent O 3,333,406 DOFFER ASSEMBLY Howard F. Parkerton, 4800 N. Van Ness Blvd., Fresno, Calif. 93704 Filed Jan. 4, 1965, Ser. No. 423,084 Claims. (Cl. 56-41) This invention relates to an improved doifer assembly for use in mechanical cotton pickers, and particularly to a doifer having separable hub and web portions to facilitate fabrication, parts distribution, and replacement in the eld.

Prior to the present invention, commercial embodiments of cotton picker dolfers have generally been in the form of an integral doifer, including a hub element, an annular web, and a plurality of doffing elements secured to the Web near its peripheral edge. In some form, the hub is fabricated of a suitable metal, such as steel, and is provided with an integral radially extending angelike web. The doing elements in this form are fabricated of a rubber of a selected durometer hardness. The rubber doiiing elements are then bonded to the web, either individually, or by means of an interconnecting membrane to provide greater surface of adhesion. In other forms of doffers, the hub and web portions are constructed of a tough, slightly resilient material, such as a rubber phenolic, while the dofling elements are formed of rubber vulcanized and compounded to give the desired degree of hardness. An example of such a construction is that described in my U.S. Patent No. 2,693,071.

While extremely satisfactory dofling is performed by such pervious structures, this type of integral structure does not facilitate replacement of the doffers or dofng elements under conditions encountered during field operations. For example, many commercial pickers employ a sen'es of doifers mounted in vertically stacked arrangement on a single shaft. A series of such stacked doifers, frequently as high as twenty in number, cooperate with a cotton picker carrier in removing cotton from the picking spindles of the carrier. Under normal operating conditions, cotton lint becomes wrapped about the rotating parts of the picker, including the shaft and hubs of the individual doiers.

During picking operation, cotton is mechanically removed by frictional engagement of the cotton on the spindles by the individual doing elements. Consequently, when the rubber dofling elements have become worn to the point of inefcient performance requiring replacement, the doifers must be removed from the shaft, and replaced by new dotfers. Alternatively, the individual doing elements must be replaced on each doifer. Since the hub and integral web present a considerable amount of capital investment to the owner of the cotton picker, it formerly was more economical to remove the worn doing elements and replace them with new ones of the original size.

During replacement of worn dofling elements, the sequence required inspection of the dolfers by representatives of the United States Department of Agriculture to insure that lint wrapped about the individual parts did not contain boll weevils and/ or other insects which might attack cotton plants. The doffer is then placed in a tank containing a solvent for the adhesive employed in bonding the doing elements to the web. Subsequent to removal of the dofling elements, the web is cleaned and dried and a new set of dofling elements bonded thereto. The doifer bearing the new doiiing elements is then returned to the owner for replacement in the cotton picker. Alternatively, such re-conditioned doifers are maintained in stock, so that an exchange can be made to cotton picker owners to avoid delay in securing replacement dofling elements.

3,333,406 Patented Aug. 1, 1967 ice If a cotton picker owner returns the original doifers following restoration of the doing elements to their original respective positions in the picker, a minimum amount of adjustment relative to the picking spindles normally ensues. However, if shims are required on any of the dofers so as to provide satisfactory axial positioning of the doffer on its supporting shaft, these shims must be returned to their original position, otherwise mal-adjustment and poor doing will result. Consequently, this requires the owner to note the position and quantity of any shims employed, as well as the respective locations of the doffers in the vertical stack.

Alternatively, if replacement dolfers are acquired on an exchange basis, the machine owner must inspect and adjust for relative positioning between each doffer and series of spindles with which the the doffer cooperates. As a result, replacement of doffers in a cotton picker has previously been a rather expensive, tedious, and time consuming procedure.

Accordingly, it is a principal object of the present invention to provide an improved doifer assembly which achieves an economy of production and ease of replacement in the iield.

Another object is to provide a doifer assembly fabricated of separable hub and web portions which reduces the cost of replacing worn dofiing elements.

Another object is to provide an improved doffer which is dependable in operation and which is easily replaced upon reaching the limit of its normal service life.

Another object is to provide a dolfer assembly which insures uniformly spaced doing elements which are precisely located with respect to the picking spindles.

Another object is to provide an improved dolfer assembly which permits utilization of low-cost production methods and minimizes costly machine tooling operations, while achieving accuracy of manufacture and uniformity of piece parts.

A further object is to provide an improved doer assembly which effects economy in shipping, storage, and replacement of spare parts.

These, together with other objects, will become more fully apparent upon reference to the following description and accompanying drawings.

In the drawings:

FIG. l is a top plan view of a vertically stacked series of doifer assemblies embodying the principles of the present invention shown in cooperating relation with the picking spindles of a carrier assembly of a conventional mechanical cotton picker, shown fragmentarily.

FIG. 2 is an enlarged fragmentary view in elevation, partly in section, taken along the line 2--2 of FIG. l.

` FIG. 3 is an enlarged view in vertical transverse section showing the components in a disassembled relation, a portion of the hub element being shown fragmentarily in assembled position to illustrate dimensional differences between certain components.

FIG. 4 is a view in front elevation showing the web portion of separate dofer assemblies in nested relation for shipment and/or storage.

Referring in greater particularity to FIG. l, a picker carrier is fragmentarily illustrated at l0 as typical of cylindrical carriers mounted in conventional mechanical cotton pickers for rotation about an upright axis in a clockwise direction, as viewed. A plurality of circumferentially spaced picker bars 11 are mounted for pivotal movement about respective upright axes in the carrier and controlled by suitable cam mechanism, not shown, and which forms no part of the present invention.

Each of the picker bars supports a plurality of axially spaced spindles 12 mounted for rotation about respective axes, approximately horizontal but inclined slightly thereto, so that the upwardly disposed portion of each spindle periphery lies in a substantially horizontal plane. During rotation of the carrier, the spindles progress through a picking zone, generally indicated at 13, and are subsequently moved through a dofng zone 14. The spindles are formed with a substantially conical outer surface 15, which is provided with a means for picking or snagging cotton extending from a tip 16 inwardly toward the root of the spindle in the form of a plurality of barbs or teeth 17. As is well known in the art, rotation of the spindles through the picking zone results in cotton being snagged by the barbs 17 and wrapped around the individual spindles. Subsequent travel of the spindles in their circuitous path moves the spindles with the cotton Wrapped therearound through the doing zone 14.

As can be seen in FIGS. l and 2, a plurality of doifer assemblies 20 are carried in contiguousy axially spaced relation on a shaft 21 which is mounted in the picker by means, not shown, for rotation about an upright axis substantially parallel to the axis of the picker carrier 10. In commercial forms of mechanical cotton pickers, the number of vertically spaced spindles 12 is frequently twenty, with a coresponding number of vertically spaced doffer assemblies 20. A retaining flange 22 is provided on the shaft to limit movement of the doffer assemblies, as Well as to provide a reference point for positioning of the dolers in relation to the spindles 12. It will be appreciated that a precise relation must exist between the spindles and the doiers to insure efficient removal of cotton wound about the spindles. A nut 23 is screW-threadably retained on the shaft 21 and, by means of a washer 24, axially compresses the doffer assemblies 20 into frictional engagement to impart rotational driving force thereto.

Each of the dolfer assemblies carries a plurality of circumferentially spaced doing elements 25. These elements are provided with respective do'ing faces 26 adapted to engage the upwardly presented portion of the spindle surface during rotation of the shaft 21. As can be seen in FIG. 2, the respective dofting faces 26 of the dofing elements 25 are disposed in a common diametral plane substantially normal to shaft 21.

As more clearly illustrated in FIG. 3, the doffer assembly includes a separable hub member 30 having opposite axially spaced first and second faces 31 and 32. A flange 33 is provided intermediate the axially spaced faces and is spaced from the first face at a distance indicated by L1. The hub -member is also provided with a tapered pilot portion 34, which is substantially coextensive with the distance L1.

The doter assembly 20 also includes an annular web member 40 having opposite faces 41, 42. A shoulder 43 of uniform thickness circumscribes a central aperture 44 adapted to receive the tapered pilot portion 34 of the hub member 30. The shoulder is of a thickness T1 slightly greater than the distance between the face 31 and flange 33 of the hub, indicated by L1. This difference in respective dimensions is designated D1 in FIG. 3. In a commercial embodiment of the invention, this difference in dimensions is in the order of .005. In this commercial embodiment, the hub member is fabricated of aluminum by a die casting method, with machining limited to a facing operation of face 32 to determine the axial distance between faces 31 and 32, indicated as L2 in FIG. 3, and a boring operation for precise dimensional control of the inside diameter.

In addition to the shoulder 43, the remainder of the annular web 40 is in the for-m of a radially tapered body 45 which slopes outwardly along face 41 while maintaining face 42 in a diametral plane. The tapered body terminates in a circular peripheral edge 46 circumscribing an annular recess 47 formed in the face 42 in concentric relation to the aperture 44. The recess 47 is dimensioned to receive the ange 33 of the hub 30 as shown fragmentarily in FIG. 3.

A relatively thin membrane 50 is formed in interconnecting integral relation with the dofiing elements to facilitate bonding of the elements to the face 42 of the annular web member 40. In the aforesaid commercial embodiment, the web member is formed of a rubber phenolic which provides sufficient structural strength to support the dofting elements and to permit the driving torque force between adjacent doffer assemblies, yet provides limited resiliency to absorb shock loads imposed thereon without fracturing the web. In addition, the inherent resiliency of such rubber phenolics permits axial compression of the shoulder portion 43 suicient to permit contact between the face 31 of one hub member with the face 32 of a contiguous member. Prior to such compression, the distance measured from the face 41 of the shoulder 43 to the face 32 of the hub member with the liange 33 received within recess 47 is of a thickness indicated by T2 and is slightly greater than the length L2 between the axially spaced faces 31, 32. Consequently, upon axial compression of shoulder 43, the thickness T2 is substantially equal to the length L2, since total axial compression is limited by the metal hub 30.

Operation The operation of the described embodiment of the subject invention is believed to be readily apparent and is briefly summarized at this point. During initial assembly of a cotton picker incorporating doffer assemblies of the present invention, the shaft 21 is installed in the picker with the flange 22 in a predetermined position oriented with respect to the spindles 12. Since the individual spindles are uniformly spaced along the picker bars 11, a predetermined spacing exists for the doffer assemblies 20 so as to dispose the doffing faces 26 of the dofng elements in respective diametral planes in wiping engagement with the upwardly presented portions of the respective spindle surfaces 15. In certain forms of dofers, the individual doffers are driven by a key partially received in a keyway formed in the shaft as well as respect1ve keyways provided in the individual doffers. With the present invention, assembly of the series of `doffers is not impeded by the requirement of insertion of an elongated key and angular rotation of the individual doier assemblies to insure alignment of the keyway with the key.

As distinguished from such a method, the present invention permits an ease of assembly of the individual web members 40 with corresponding hub member 30 and axial sliding upon the shaft 21, until an appropriate number of assemblies has been mounted on the shaft. Subsequently, the washer 24 and nut 23 are used to effect an axial loading of the stack of doifer assemblies. Axial compression is continued until each of the individual shoulder portions 43 of each web 40 is compressed so that the thickness T2 is substantially equal to the length L2, representing the axial distance between the opposite faces 31, 32 of each hub member. When such axial compression has been made, the limited resiliency of the web 40 insures maintenance of the axial loading, while the rigidity of the hub member limits total axial compression. Consequently, sufficient loading is available to transmit the driving torque forces While accurate positioning of the individual dolfer assemblies is insured by the rigidity of the hub members.

In the event that the individual doing elements 25 of any dofer assembly become worn beyond its useful serv ice life, the web 40, including the membrane 50 bonded thereto and carrying the dong elements, can easily be replaced by a new web assembly. As shown in FIG. 4, the separability of the component parts of the doffer assembly permits packaging and positioning for minimum space requirements in shipping and/or storage. Since substantially no wear of the hub member occurs during normal operations, the hub member is capable of use throughout repeated replacement of the annular web 40 carrying the dotiing elements.

Accordingly, the invention permits utilization of lowcost mass production of the hub member with a minimum of machine tooling operation. The invention also lends itself to molding fabrication of the web member 40, and conventional production of the rubber dofllng elements 25. In addition, the invention insures precise location of the dolfer assemblies with respect to the spindles in the mechanical cotton picker. Shipping, storage, and field replacement of the individual web members is readily permitted, without the necessity of costly `doffer element removal and rebonding procedures. Consequently, the invention provides an economy in the manufacture and maintenance of mechanical cotton pickers heretofore not experienced.

Although the invention has been herein shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An improved doffer assembly for cotton picking machines comprising an annular web circumscribing a central aperture and providing opposite faces and a peripheral edge; a plurality of axially extended circumferentially spaced dofiing elements carried by the web adjacent to said edge and providing respective axially facing surfaces disposed in a common diametral plane; and a separable hub member having opposite axially spaced first and second faces, a radial flange intermediate the faces, and a pilot portion extended axially from the flange toward the first face and disposed within said central aperture with the flange in engagement with one of the faces of the web.

2. The doifer assembly of claim 1 wherein said pilot portion is of an axial dimension less than the thickness of said annular web immediately circumscribing the central aperture.

3. The `doffer assembly of claim 2 wherein said `web is formed of a material permitting axial compression to a thickness substantially equal to said axial dimension of the pilot portion.

4. In a cotton harvester having adjacent axially spaced members mounted on a shaft for frictional driving engagement between the members, an assembly for one of said members comprising a tubular hub axially slidable on the shaft and having axially spaced rst and second faces and a radial flange intermediate the faces, and being provided with a pilot portion extending axially from the flange toward the first face; an annular web portion having a central aperture disposed on said pilot portion and providing opposite faces, one of which is in engagement with said flange and the other in driving frictional engagement with another adjacent member, wherein said web portion measured between said flange contacting face and said opposite face is of a greater thickness than the distance between the first face of said hub member and said flange, and said web member is fabricated of a material more compressible than said hub member so that axial loading of said assemblies effects compression of the web between the flange and said adjacent assembly.

5. A doffer assembly for a cotton picking machine comprising an annular web having a shoulder portion circumscribing a central aperture and being of a predetermined rst thickness and having a peripheral edge; a plurality of circumferentially spaced dofllng elements extended from one of said faces and carried by the web adjacent to said edge, said elements providing respective axially facing contacting surfaces disposed in a common diametral plane; and a hub member having opposite axially spaced first and second faces and a radial flange intermediate the faces, the axial length measured from said first face to said flange being of a first length less than said first thickness, and the axial length between said first and second faces being of a second length, said hub member being provided with a pilot portion extending axially from the flange toward the first face and disposed within said central aperture with the flange in engagement with one of the faces of the web, said web being constructed of a material of limited compressibility so that when assembled with the pilot portion in said aperture and the flange in contact with said shoulder, the assembly .provides a combined first thickness measured from the other face of the web to said second face of the hub and greater than said second length with the assembly in a free, unstressed condition, and when the assembly is subjected to a determined axially compressing force, the assembly provides a combined second thickness measured from the other face of the web to said second face of the hub with said second thickness being substantially equal to said second length.

6. An improved doffer assembly for use in cotton picking machines comprising an annular web member formed of a substantially rigid material of limited compressibility and having a central aperture defined by a shoulder portion integral with the web, the web providing opposite faces and a peripheral edge, the shoulder being of a first thickness; a tubular hub member formed of a material having greater rigidity than that of the web and permitting substantially no compressibility under normal operating conditions, the hub having axially spaced first and second faces, a radial flange intermediate the faces, and a pilot portion extending axially from the flange towa-rd the first face, said portion disposed in said aperture and being of a length less than said first thickness of the shoulder portion of the web; and a plurality of circumferentially spaced dofling elements bonded to the web adjacent to said peripheral edge.

7. rl`he doffer assembly of claim 6 wherein said web is formednof a rubber phenolic and said doffing elements are formed of an elastomer having greater resiliency than said rubber phenolic.

8. The doifer assembly of claim 6 wherein said doing elements are formed integrally with an interconnecting menbrane to facilitate positioning on and bonding to the we 9. An improved dolfer assembly for cotton picking machines comprising an annular web circumscribing a central aperture and providing opposite faces and a peripheral edge, the web being formed of a material having a predetermined thickness in a free, unstressed state and permitting predetermined axial compression; a plurality of axially extended circumferentially spaced dofling elements carried by the web adjacent to said edge and providing respective axially facing surfaces disposed in a common diametral plane; and a separable hub member having opposite axially spaced first and second faces, a radial flange intermediate the faces, and a pilot portion extended axially from the flange toward the first face and `disposed within said central aperture with the flange in engagement with one of the faces of the web, said pilot portion being tapered from said flange and being of an axial dimension less than said predetermined thickness of said unstressed annular web immediately circumscribing the central aperture.

10. A doffer assembly for cotton picking machines and the like comprising a plurality of annular web members of a substantially rigid material of limited compressibility circumscribing respective central apertures and providing opposite faces and peripheral edges; a plurality of circumferentially spaced dofling elements axially extended from corresponding faces of the web members adjacent t-o said edges thereof; a plurality of hub members of substantially non-compressible material, the hub members and the web members being stacked in alternately superimposed relation, the hub members having peripherally extended flanges with adjacent hub members having their respective intermediate web members disposed between said flanges; and means extended through the web and hub members axially compressing said members to grip the web members between the anges of the hub members, the hub members being dimensioned to dispose the doftng elements in predetermined axially spaced relation and with the web members compressed therebetween comprising a column resistant to further compression,

8 References Cited UNITED STATES PATENTS 2,688,225 9/1954 Morkoski et al 56--44 3,151,432 10/1964 Sadler 56-41 ABRAHAM G. STONE, Primary Examiner.

RUSSELL R. KINSEY, Examiner. 

1. AN IMPROVED DOFFER ASSEMBLY FOR COTTON PICKING MACHINES COMPRISING AN ANNULAR WEB CIRCUMSCRIBING A CENTRAL APERTURE AND PROVIDING OPPOSITE FACES AND A PERIPHERAL EDGE; A PLURALITY OF AXIALLY EXTENDED CIRCUMFERENTIALLY SPACED DOFFING ELEMENTS CARRIED BY THE WEB ADJACENT TO SAID EDGE AND PROVIDING RESPECTIVE AXIALLY FACING SURFACES DISPOSED IN A COMMON DIAMETRAL PLANE; AND A SEPARABLE HUB MEMBER HAVING OPPOSITE AXIALLY SPACED 